While undercover in the confessional booth Detective Ruz told the priest she changed the door code to the day of Saint Dwynwen (subtitles incorrectly spell it "Dwynwyn"). Saint Dwynwen, sometimes known as Dwyn or Donwen, is the Welsh patron saint of lovers (and injured animals), she is celebrated in Wales on January 25th. There are few actual historical accounts of Dwynwen, most of what is known about her comes from legend and folktale. Dwynwen was thought to be the daughter of King Brychan Brycheiniog, who ruled Wales in the early to mid 5th-century A.D. Legend says that Dwynwen was in love with a young man named Maelon Dafodrill, but her father refused to grant her hand in marriage to him. Distraught with grief over not being able to be with the man she loved Dwynwen prayed to God for her to fall out of love with him so she wouldn't have to feel the pain of heartbreak and loneliness. An angel of the Lord appeared to her and said God heard her prayer and created a potion that would cause her to fall out of love, but that it would take a sacrifice on her part: she would have to agree to never marry, remain a virgin and live in solitude for the rest of her life. Dwynwen agreed and moved to Ynys Llanddwyn, a small island off the coast of Wales. She built a church on the island, and after she died around 460 A.D. stories spread about a sacred fish appearing in the church's pond whose movements could predict the fate of the relationship of lovers. These stories caused the Church of Dwynwen to became a sacred shrine during the Middle Ages, couples from across Wales would make a pilgrimage to the church on January 25 to see the sacred fish and learn the fate of their relationship. The Protestant Reformation of the 16th-century caused the shrine to become forbidden, as it and the fish were considered to be pagan idols; though by the late 19th-century the church and shrine began to be visited again as a reform in Protestant churches caused local traditions to become no longer forbidden or taboo.
Saint Dwynwen is not officially recognized or commemorated by the Anglican or Catholic Church, however many Anglican and Catholics from Wales still commemorate her on January 25th.